The present invention relates generally to the field of cooling systems for air-cooled internal combustion engines.
Many air-cooled engines include a blower housing and a rotating screen. The rotating screen is positioned over a flywheel and a fan coupled to the crankshaft of engine. As the engine operates, the flywheel, the fan, and the rotating screen rotate with the crankshaft. Under this configuration, cooling air is drawn into the blower housing to cool the engine, while the rotating screen acts to prevent debris from entering blower housing and/or to break or cut any debris entering the blower housing into relatively small pieces. Because of the rotation of rotating screen, debris is not able to quickly build up on the rotating screen and restrict airflow across the engine. However, there may be instances where access to moving parts of the engine, including a rotating screen, must be restricted. Also, the rotating screen may restrict air flow into the blower housing.
Additionally, in many air-cooled engines, the flywheel, the fan, and the rotating screen are coupled to the crankshaft of engine to rotate when the engine is operational. However, due to this coupling, the fan, and the rotating screen are only able to rotate in one direction and are only operational when engine is running. Additionally, because the fan is coupled to the crankshaft, the location and orientation of the fan is limited by the location of the crankshaft.
In engine configurations that do not require the ignition trigger coils to be located adjacent the flywheel (e.g., electronic fuel injection systems), the exact placement of the ignition trigger coils may be varied without adversely affecting the operation of the engine. Some engine manufacturers mount the ignition trigger coils externally on a side of the engine/blower housing. However, this placement opens the ignition trigger coils up to debris and incidental contact.
It would be advantageous to provide a cooling system for an air-cooled internal combustion engine that effectively restricts access to moving parts while still allowing for sufficient airflow and debris management.